Nature is the master of genetic shuffling and is constantly sorting and resorting DNA, causing both subtle and profound changes in all living things. People first began their own DNA management thousands of years ago, when they began crossbreeding plants to produce better foods or fiber. In 1953, scientists discovered the structure of DNA, and in 1973, researchers developed a method for cutting and splicing DNA. That method became known as recombinant DNA, or rDNA, because it enabled scientists to cut and recombine segments of DNA. Since then, researchers have learned how to move genetic material in the form of DNA from one plant or animal to another.
Genetic modification is much more precise than selective breeding. By transferring only certain genes from one plant or animal to another, researchers can introduce one specific trait without also transferring dozens of unwanted traits, as often occurs in selective breeding. And genetic modification is the only existing tool available for producing certain vaccines, drugs and diagnostics. Genetic modification in plants has been going on since the early 1980s. In 1986, EPA approved commercial growing of the first genetically engineered crop - tobacco plants resistant to a tobacco virus.